My CMMG WASP .22LR dedicated AR upper (on a PSA lower) has been incredibly reliable on a wide variety of ammo. In several thousand rounds, I can only recall one malfunction (a failure to fire due to bad bulk ammo).

In fact, it has been more reliable than my Ruger 10/22. It is also MUCH more accurate out-of-the-box.

Here is a link to a report of my experience with my CMMG dedicated .22LR AR upper: